1. Field of the Invention
This invention relates generally to apparatus for magnetically treating a liquid flowing through a pipe, and pertains more particularly to unpotted units that can be readily held in place against the exterior of the pipe to be serviced.
2. Description of the Prior Art
Perhaps U.S. Pat. No. 4,367,143 issued to Roland K. Carpenter on Jan. 4, 1983 for APPARATUS FOR MAGNETICALLY TREATING LIQUID FLOWING THROUGH A PIPE AND CLAMPING MEANS THEREFOR is representative of the state of the art. However, as mentioned in the applicant's issued Patent '143, U.S. Pat. No. 3,328,878 granted on Jan. 11, 1966 to Dean L. Moody for METHOD AND APPARATUS FOR TREATMENT OF FLOWING LIQUIDS TO CONTROL DEPOSITION OF SOLID MATTER THEREFROM also is representative of earlier prior art. As with the applicant's Patent '143 and Patent '878, both disclosures mention scale and paraffin problems, pointing out that scale can take various forms but typical of the substances creating scale problems are calcium carbonate, calcium sulfate, barium sulfate, sodium chloride, magnesium sulfate, silica, as well as various oils, waxes and greases in addition to paraffin. Accumulations of these substances on the interior of the pipe obviously produce problems, especially as far as causing a greater resistance to liquid flow within the pipe, and also where heat is applied to the pipe's exterior, the collected substances act as an objectionable thermal insulator. Sufficient accumulations, quite obviously, require that the piping system be inactivated and the pipes individually cleaned out, a time-consuming and costly procedure where the system is an industrial one, particularly due to the fact that the particular piping system is not productive during the shutdown period.
The polarization of diamagnetic materials through the agency of relatively strong magnetic fields provided by permanent magnetic means is generally well understood and need not be repeated at this time, although reference may be made to either of the patents herein referred to for a basic understanding of what is involved. Very succinctly, however, the principle behind the polarization is to prevent the formation of sufficiently objectionable deposits on the inside of the pipe, the magnetic action causing the diamagnetic materials to move inwardly under the influence of the sufficiently strong magnetic field provided by the two alluded to patented arrangements and which is even better achieved with the present invention as will soon become manifest. The difficulty is that with large diameter pipes the mounting of suitable permanent magnetic apparatus has posed a problem. Also, the cost per unit where a potting compound is used has proven to be unduly high, especially where large-diameter pipes are involved.
Examples of where large-diameter pipes are employed are at pipe line terminals where crude oil is transferred from a pipe line to a tanker after first having been stored in one or more settling tanks. Inasmuch as the moisture content for shipping crude oil must be less than 1.0%, chemicals are also used as dessicants to dehydrate the oil. The result is that basically three separations are obtained in the tank: (1) the oil that rises to the top, (2) the water that goes to the bottom, and (3) an intermediate emulsion layer containing oil and water. Obviously, the less emulsion, the better because it is a waste product (as of course is the amount of water that must be removed); however., whatever oil is contained in the emulsion is also lost, so it is extremely advantageous to minimize the amount of emulsion that is produced. Without my invention, a large tank has been needed, filled, chemicals added, and the contents allowed to statically set for at least 24 hours to dehydrate the water down to the required sufficiently low level. With my magnetic apparatus applied to the pipe line just before it enters the tank, the oil may be taken out of the tank almost immediately in that there is a higher percentage of oil and water separating with a concomitantly lesser amount of emulsion being formed. The tank, therefore, can be much smaller, the process being virtually continuous.